docs: def get_throttled_write_event_count(
          table_name, gsi_name, lookback_window_start=15, lookback_period=5):
      """ Returns the number of throttled write events during a given time frame
  
      :type table_name: str
      :param table_name: Name of the DynamoDB table
      :type gsi_name: str
      :param gsi_name: Name of the GSI
      :type lookback_window_start: int
      :param lookback_window_start: Relative start time for the CloudWatch metric
      :type lookback_period: int
      :param lookback_period: Number of minutes to look at
      :returns: int -- Number of throttled write events during the time period
      """
      try:
          metrics = __get_aws_metric(
              table_name,
              gsi_name,
              lookback_window_start,
              lookback_period,
              'WriteThrottleEvents')
      except BotoServerError:
          raise
  
      if metrics:
          throttled_write_events = int(metrics[0]['Sum'])
      else:
          throttled_write_events = 0
  
      logger.info('{0} - GSI: {1} - Write throttle count: {2:d}'.format(
          table_name, gsi_name, throttled_write_events))
      return throttled_write_events